This invention relates to an information reproducing apparatus for reproducing information recorded on an information recording medium, an authenticating apparatus for effecting the authentication process, and an information processing system for transferring information by effecting the mutual authentication between a first apparatus and a plurality of second apparatuses.
Conventionally, an apparatus for reproducing information mixedly containing video information, audio information and still picture information recorded on an optical disk such as a DVD by use of an optical disk device is realized. Information reproduced by the optical disk device is processed by a processing circuit according to the type of information.
For example, if information contains MPEG video data, audio data (PCM, AC3), sub-picture data, navigation data and the like, information is processed by processing boards corresponding to the respective data items.
In this case, the main controller temporarily fetches data items and distributes the fetched data items-to the respective processing boards according to the types of the data items.
In this case, in a period of data distribution, the main controller is occupied. Therefore, if the amount of information reproduced from the optical disk device becomes large, the load of the main controller is increased and the main controller cannot effect other processes for a long period of time.
Further, conventionally, as a bidirectional subject authentication method known as the encoding (obfuscating) technique, a method using an electronic signature by use of a public key(asymmetric key) such as an RSA (public key encryption algorithm) is well known.
For example, the following methods are well known.
1] xe2x80x9cAxe2x80x9d transmits a random character to xe2x80x9cBxe2x80x9d as xe2x80x9cchallengexe2x80x9d.
2] xe2x80x9cBxe2x80x9d signs the character with the public key which xe2x80x9cBxe2x80x9d has and sends back the character to xe2x80x9cAxe2x80x9d as xe2x80x9creportxe2x80x9d. xe2x80x9cAxe2x80x9d inquires of an authentication station (CA center) which is a third party storing the public key of xe2x80x9cBxe2x80x9d and decodes (deciphers) information returned from xe2x80x9cBxe2x80x9d by use of the public key from the authentication station. If the result of decipher coincides with the character which xe2x80x9cAxe2x80x9d first transmitted, xe2x80x9cBxe2x80x9d is identified as the person himself.
3] xe2x80x9cBxe2x80x9d transmits a random character to xe2x80x9cAxe2x80x9d as xe2x80x9cchallengexe2x80x9d.
4] xe2x80x9cAxe2x80x9d signs the character with the public key which xe2x80x9cAxe2x80x9d has and sends back the character to xe2x80x9cBxe2x80x9d as xe2x80x9creportxe2x80x9d. xe2x80x9cBxe2x80x9d inquires of an authentication station (CA center) which is a third party storing the public key of xe2x80x9cAxe2x80x9d and decodes (deciphers) information returned from xe2x80x9cAxe2x80x9d by use of the public key from the authentication station. If the result of decipher coincides with the character which xe2x80x9cBxe2x80x9d first transmitted, xe2x80x9cAxe2x80x9d is identified as the person himself.
However, with the above method, the third party (authentication station (CA center)) storing the public key is required, it is necessary to inquire of the authentication station (CA center) which is the third party storing the public key by communication at each time of bidirectional subject authentication, and thus the process becomes extremely complicated.
Further, when the public key which the third party manages is used, the public key tends to be stolen and the security protection is difficult.
A method for mutually exchanging encoding (obfuscating) keys is known in the prior art, but the way the mutually exchanged encoding keys are used is little known except a case wherein the encoding key is used to encode transfer information.
Further, with the above method, when the place in which the other party to be authenticated is previously known, information to be transmitted is determined, and the other party to whom information is transmitted (to be authenticated) is searched for, the above method cannot be used. That is, conventionally, no effective method is proposed for a method for searching for the other party to be authenticated.
This invention can transfer data between an information reproducing apparatus and processing boards without using a main controller and can alleviate the load of the main controller and thus the main controller can effect other processes during the information transferring period.
Further, this invention can effect the encoding (obfuscating)/decoding (deciphering) process in an extremely simple construction.
This invention can easily effect the mutual authentication operation without using a third party which manages public keys, that is, this invention can make it unnecessary to use the third party or inquire of the third party and can effect the mutual authentication operation extremely easily with high reliability.
Further, this invention can prevent leak of information with reliability extremely higher than a case wherein the public key system is used by further obfuscating an obfuscating key by use of the transferred obfuscating key.
In this invention, an authentication object (which is to be authenticated) is identified based on information (stream ID) indicating the type of information attached to information transmitted from the information recording medium, each authentication object is authenticated, then information can be distributed (transmitted) to the authentication objects in parallel, and as a result, the load of the authentication object is relatively alleviated and information can be displayed on the display screen in a short period of time after reproduction of information from the information recording medium is started, and time lag can be suppressed to minimum.
In this invention, the authentication object can be searched for based on information to be transmitted, and the authentication object can be searched for by use of the relatively simple method by supplying information to candidates of the authentication object, causing the candidates to send back responses and effecting the mutual authentication operation based on the results of responses.
Further, in this invention, since an obfuscating information storing memory provided in an authentication functional section, information can be arranged in order by using a clock which is independent from the memory. Since obfuscated information is previously recorded on an external transfer data storing section by use of the clock inherent to the authenticating functional section, a data transfer interface section can record/reproduce information with respect to the external transfer data storing section at an optimum timing according to the state of the transmission line. By temporarily storing obfuscated information transferred with respect to the exterior in the external transfer data storing section and independently forming obfuscated information according to the inherent clock provided in the interior, the adaptability at the time of protocol conversion and the flexibility for the busy condition of the external communication line can be enhanced.
Further, in this invention, by previously storing an area key and stream key in the authentication information storing section and using the information for the authentication process, it becomes unnecessary to use the third party such as an authentication station (CA center) or inquire of the third party and the mutual authentication operation can be extremely easily effected with high reliability.
Further, in this invention, since only a client (IP address or telephone number thereof) to or by whom information is distributed or collected and the content of the information to be distributed or collected are informed from the server and the other processes are left to the information reproducing apparatus, no load is imposed on the main CPU during the information transfer and the main CPU can effect the other process during the information transfer so that the high speed process can be attained as a whole system. Further, since information is input/output via the network communication between the computer and the information reproducing apparatus, the information reproducing apparatus can be placed at a far distance from the computer, and as a result, the computer can be installed in a small space.
In this invention, since the information reproducing apparatus has a communication function, the information input/output process can be attained between the information reproducing apparatuses during the communication if a communication LAN card or modem card is used in a small PC such as a small note PC having only one PCMCIA card slot. Further, since obfuscated information can be transmitted to the information reproducing apparatus having an authentication function, neither copying of information nor leakage of information in the communication path will occur.
Not only the communication functional section is provided but also the authentication functional section is provided to effect mutual authentication with respect to the authentication object by use of the communication function of the communication functional section and transmit obfuscated information so that information leakage by copying information during the network communication can be prevented and the high-level security can be attained.
Further, in this invention, by storing the authentication histories of a plurality of authentication objects in the memory, the authentication processes can be simultaneously effected for and obfuscated information can be simultaneously transmitted to a plurality of authentication objects by use of the time-sharing processing method, and an authentication object will not have to wait for a long time for authentication and the authentication processes with respect to a plurality of authentication objects can be simultaneously effected at high speed.
Further, in this invention, since issuance of an obfuscation key, obfuscation of information and decoding (decipher) of obfuscated information can be effected by use of one random signal generator, the circuit can be simplified and the cost is lowered by combining the functions.
Further, in this invention, the authentication process can be effected between boards in the personal computer.
According to one aspect of this invention, there is provided an information reproducing apparatus for reproducing information recorded on an information. recording medium, which comprises authentication means for authenticating a specified authentication, object other than the information reproducing apparatus, and output means for outputting data reproduced from the information recording medium to the specified object authenticated by the authentication means.
According to still another aspect of this invention, there is provided an information reproducing apparatus for reproducing information recorded on an information recording medium, which comprises communication means for transferring information to a specified authentication object other than the information reproducing apparatus; authentication means for authenticating the authentication object by use of the communication means; and output means incorporating the communication means, for outputting data reproduced from the information recording medium to the object authenticated by the authentication means.
According to another aspect of this invention, there is provided an authenticating method comprising the steps of individually receiving first obfuscation keys from a plurality of authentication objects; individually issuing second obfuscation keys to a plurality of authentication objects; and forming a common obfuscation key with each of the authentication object by use of the first obfuscation key received from the authentication object and the second obfuscation key issued to the authentication object; wherein the histories of the processes of the above steps with respect to a plurality of authentication objects are separately and sequentially stored and a plurality of authentication processes are effected in parallel based on the stored histories of the processes.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The object and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.